Is it possible to save trained PQ encoder, and load it as pretrain for next time?

[wenmingwei]

I have a 2M vector database, and using PQ512x4fs with faiss. is_trained is required for every startup. it cost many times.

My question is:
is it possible to save trained PQ encoder as a pretrain encoder for IndexPQ?

Thank you.

[wenmingwei]

My draft thought is

1. do pretrain

1. train index, do not add any data to index
2. use faiss::write_index to save index to a file

2. use pretained index

1. use faiss::read_index to load index from a file
2. add data to index
3. do search

is it correct? thank you very much.

[bshethmeta]

Yes, you should be able to do that.